When a user of a mobile communications terminal moves in a geographical zone covered by different PLMNs, and cannot receive communications over the current network, then the mobile communications terminal has to search for a new network providing a better communications condition.
The technical specification 3GPP TS 31.102 prepared by the group of 3rd Generation Partnership Project (3GPP) proposes a priority configuration of a radio access technology (RAT) in which one or more radio access technologies (RAT) are made associated with one PLMN. According to this, a mobile communications terminal grants a priority to the radio access technology (RAT) that has the highest priority to search for a network present in the environments every time it loses a network coverage. A communications company or a subscriber can set a priority level in the SIM card. A PLMN associated with a radio access technology (RAT) set by the communications company is specified by an Operator PLMN (OPLMN), and a PLMN associated with a radio access technology (RAT) set by the user is specified by a User PLMN (UPLMN). Priority setting is stored in a list saved in the SIM card of the mobile communications terminal.
A drawback of the related art described above arises from the fact that, when the terminal searches for a PLMN that is clearly not listed in the list of the SIM card, a radio access technology (RAT) is randomly selected, and the selection of the radio access technology may not suit a user's need and/or may not suit the characteristics of a communications company with respect to accepting of roaming and/or with respect to financial benefit. When the mobile communications terminal finds a PLMN that is not associated with a RAT having a priority in the SIM card, this above described situation may occur.
An exemplary object of the present invention is to solve the problems of the related art described above.
Another exemplary object of the present invention is to shorten the amount of time that a mobile communications terminal needs to search for a communications network in order to limit consumption of a battery power in the mobile communications terminal.